Correction of X-ray Intensities From Single Crystals Containing Lattice-Translocation Defects

Acta Crystallogr D Biol Crystallogr. 2005 Jan;61(Pt 1):67-74. doi: 10.1107/S0907444904026721. Epub 2004 Dec 17.

Abstract

In 1954, Howells and colleagues described an unusual diffraction pattern from imidazole methemoglobin crystals caused by lattice-translocation defects. In these crystals, two identical lattices coexist as a single coherent mosaic block, but are translated by a fixed vector with respect to each other. The observed structure is a weighted sum of the two identical but translated structures, one from each lattice; the observed structure factors are a weighted vector sum of the two structure factors with identical unit amplitudes but shifted phases. A general procedure is described to obtain the unit amplitudes of observed structure factors from a realigned single lattice through an X-ray intensity correction. An application of this procedure is made to determine the crystal structure of phi29 DNA polymerase at 2.2 A resolution using multiple isomorphous replacement and multiwavelength anomalous dispersion methods.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacillus Phages / enzymology*
  • Crystallization
  • Crystallography, X-Ray / methods*
  • DNA-Directed DNA Polymerase / chemistry*
  • Macromolecular Substances
  • Models, Molecular
  • Models, Statistical
  • Molecular Conformation
  • Protein Conformation
  • Software
  • X-Ray Diffraction
  • X-Rays

Substances

  • Macromolecular Substances
  • DNA-Directed DNA Polymerase